Identification and ribotypes of Staphylococcus caprae isolates isolated as human pathogens and from goat milk

We report five cases of human infection with Staphylococcus caprae. Two were community acquired (one case each of endocarditis and urinary tract infection); the other three were acquired in a hospital (two cases of bacteremia associated with intravenous access and one case of urinary tract infection). Analysis of human isolates and goat isolates from eight herds showed that they could be misidentified by some commercial identification systems but were clearly identified as S. caprae by ribotyping, according to their species-specific ribotype. Phylogenetic methods applied to the ribotypes did not reveal two distinct lineages corresponding to the goat and human origins of the isolates, although human ribotypes were clearly distinguishable by the presence of a core of four specific bands. The latter observation may reflect some degree of evolutionary change within the species between human and goat isolates.